1 Announcements & Agenda (03/09/07) Exam next Wednesday! Covers Ch 7, 8, (not 12.6, on Exam 3) Covers Ch 7, 8, (not 12.6, on Exam 3) Practice Exam Posted! Practice Exam Posted! Review 6:30p (Room TBA) Review 6:30p (Room TBA) Come visit Bob!!! Come visit Bob!!!Today Quiz! Quiz! Properties & Reactions of Alcohols ( ) Properties & Reactions of Alcohols ( ) Ethers & Thiols ( ) Ethers & Thiols ( ) Aldehydes & Ketones ( ) (?) Aldehydes & Ketones ( ) (?)

2 One Important Example: Benzene (Know This One!) a ring of 6 C & 6 H atoms.a ring of 6 C & 6 H atoms. a flat ring structure drawn with three double bonds.a flat ring structure drawn with three double bonds. represented by 2 structures because electrons are shared among all the C atoms.represented by 2 structures because electrons are shared among all the C atoms. Last Time: Aromatic Compounds “Special Conjugation” By the way, aromatics are called as such b/c many of them have noticeable odors!

3 Last Time: A color debate! Highly conjugated pi bonds! It’s the HEME in hemoglobin!!! Note: Highly conjugated molecules are typically colored!

4 Last Time: Polymerization In polymerization, small repeating units called monomers join to form a long chain polymer. monomer unit repeats n

5 An alcohol contains a hydroxyl group (—OH) attached to a carbon chain. occur in many important molecules like sugars and -ol compounds (cholesterol, menthol, etc.) occur in many important molecules like sugars and -ol compounds (cholesterol, menthol, etc.) A phenol contains a hydroxyl group (—OH) attached to a benzene ring. water alcohol phenol water alcohol phenol Last Time: Alcohols

6 Properties of Alcohols contain polar OH groups.contain polar OH groups. form hydrogen bonds with other alcohol molecules.form hydrogen bonds with other alcohol molecules. Short alcohols (1-4 C atoms) are soluble in waterShort alcohols (1-4 C atoms) are soluble in water > 4 C atoms less soluble > 4 C atoms less soluble have much higher BPs than alkanes of similar mass.have much higher BPs than alkanes of similar mass.

7 Some Typical Alcohols (Know These) OH OH | | “rubbing alcohol”CH 3 —CH—CH 3 2-propanol (isopropyl alcohol) antifreeze HO—CH 2 —CH 2 —OH antifreeze HO—CH 2 —CH 2 —OH 1,2-ethanediol (ethylene glycol) OH OH | | glycerolHO—CH 2 —CH—CH 2 —OH glycerolHO—CH 2 —CH—CH 2 —OH1,2,3-propanetriol Could make you sick Will kill you Part of cooking oil

8 The Elixir Sulfanilamide disaster of people died 1938 Federal Food, Drug and Cosmetic Act, which required proof of safety before the release of a new drug In the 1980s similar incident happened in Haiti killing dozens of Haitian infants

9 Properties of Phenol is soluble in water.is soluble in water. has a hydroxyl group that ionizes slightly (weak acid).has a hydroxyl group that ionizes slightly (weak acid). is corrosive and irritating to skin.is corrosive and irritating to skin. + H 2 O + H 3 O +

10 Derivatives of Phenol Compounds of phenol are the active ingredients in the essential oils of cloves, vanilla, nutmeg, and mint.

11 Drawing structures revisited

12 Naming Alcohols IUPAC: Alcohols will be called somethingolIUPAC: Alcohols will be called somethingol If other functional groups present, the -OH group will sometimes be named as a “hydroxyl” groupIf other functional groups present, the -OH group will sometimes be named as a “hydroxyl” group Formula IUPACCommon Name Formula IUPACCommon Name CH 4 methane CH 3 ─OH methanol methyl alcohol CH 3 ─CH 3 ethane CH 3 ─CH 2 ─OH ethanol ethyl alcohol Also know common names for propyl alcohol and those mentioned earlierAlso know common names for propyl alcohol and those mentioned earlier

13 determined by the number of alkyl groups attached to the carbon bonded to the hydroxyl.determined by the number of alkyl groups attached to the carbon bonded to the hydroxyl. primary (1°), secondary (2°), or tertiary(3).primary (1°), secondary (2°), or tertiary(3). Primary (1º) Secondary (2º) Tertiary (3º) 1 group 2 groups 3 groups H CH 3 CH 3 | | | Primary (1º) Secondary (2º) Tertiary (3º) 1 group 2 groups 3 groups H CH 3 CH 3 | | | CH 3 —C—OH CH 3 —C—OH CH 3 —C—OH | | | H H CH 3 CH 3 —C—OH CH 3 —C—OH CH 3 —C—OH | | | H H CH 3 Classification of Alcohols

14 Reactions of Alcohols

15 Combustion of Alcohols Alcohols undergo combustion with O 2 to produce CO 2 and H 2 O. 2CH 3 OH + 3O 2 2CO 2 + 4H 2 O + Heat 2CH 3 OH + 3O 2 2CO 2 + 4H 2 O + Heat

16 Alcohols dehydrate when heated with an acid catalystAlcohols dehydrate when heated with an acid catalyst Lose —H and —OH from adjacent carbon atomsLose —H and —OH from adjacent carbon atoms H OH H OH | | H—C—C—H H +, heat H—C=C—H + H 2 O | | | | H H H H H H H H alcohol alkene alcohol alkene Dehydration of Alcohols

17 Learning Check Write the equations for the reaction of 2- propanol when it undergoes 1. combustion. 2. dehydration.

18 Solution OH OH │ CH 3 ─CH─CH 3 = 2-propanol = C 3 H 8 O 1. combustion 2C 3 H 8 O + 9O 2 6CO 2 + 8H 2 O 2C 3 H 8 O + 9O 2 6CO 2 + 8H 2 O 2. dehydration OH OH │ H + │ H + CH 3 ─CH─CH 3 CH 3 ─CH=CH 2 + H 2 O Major Product: Alkene w/ more alkyl substiuents

19 When a primary alcohol is oxidized, [O], one H is removed from the –OH.one H is removed from the –OH. another H is removed from the C bonded to -OH.another H is removed from the C bonded to -OH. an aldehyde is produced.an aldehyde is produced. [O] [O] Primary alcohol Aldehyde Primary alcohol Aldehyde OH O OH O | [O] || | [O] || CH 3 —C—H CH 3 —C—H + H 2 O CH 3 —C—H CH 3 —C—H + H 2 O | | H Ethanol Ethanal Ethanol Ethanal (ethyl alcohol) (acetaldehyde) (ethyl alcohol) (acetaldehyde) Oxidation of Primary (1  ) Alcohols This is a carbonyl group…

20 Oxidation of Secondary (2  ) Alcohols When a secondary alcohol is oxidized, [O], one H is removed from the –OH.one H is removed from the –OH. another H is removed from the C bonded to -OH.another H is removed from the C bonded to -OH. a ketone is produced.a ketone is produced. [O] [O] secondary alcohol ketone secondary alcohol ketone OH O OH O │ [O] ║ │ [O] ║ CH 3 ─C─CH 3 CH 3 ─C─CH 3 + H 2 O CH 3 ─C─CH 3 CH 3 ─C─CH 3 + H 2 O │ H 2-propanol (isopropyl alcohol) 2-propanol (dimethyl ketone) 2-propanol (isopropyl alcohol) 2-propanol (dimethyl ketone) ASK ME ABOUT “R”!!!

21 Oxidation of Tertiary ( 3)  Alcohols Tertiary 3  alcohols do not readily oxidize. [O] Tertiary alcoholno reaction OH OH │ [O] │ [O] CH 3 ─C─CH 3 no product CH 3 ─C─CH 3 no product │ CH 3 no H on the C-OH to oxidize CH 3 no H on the C-OH to oxidize 2-methyl-2-propanol

22 Oxidation of Ethanol in the Body In the body, enzymes in the liver oxidize ethanol.enzymes in the liver oxidize ethanol. aldehyde product impairs coordination.aldehyde product impairs coordination. blood alcohol over 0.4% can be fatal. O Oblood alcohol over 0.4% can be fatal. O O ║ ║ ║ ║ CH 3 CH 2 OH CH 3 CH CH 3 COH 2CO 2 + H 2 O ethanol acetaldehyde acetic acid

23 acts as a depressant.acts as a depressant. kills or disables more people than any other drug.kills or disables more people than any other drug. is metabolized at a rate of mg/dL per hour by a social drinker.is metabolized at a rate of mg/dL per hour by a social drinker. is metabolized at a rate of 30 mg/dL per hour by an alcoholic.is metabolized at a rate of 30 mg/dL per hour by an alcoholic. Ethanol CH 3 CH 2 OH

24 Effect of Alcohol on the Body

25 % EthanolProduct 50%Whiskey, rum, brandy 40%Flavoring extracts 15-25%Listerine, Nyquil, Scope 12%Wine, Dristan, Cepacol 3-9%Beer, Lavoris Alcohol Contents in Common Products

26 Ethers contains an ─O─ between two carbon groups (R-O-R’).contains an ─O─ between two carbon groups (R-O-R’). has a common name that gives the alkyl names of the attached groups followed by ether.has a common name that gives the alkyl names of the attached groups followed by ether. CH 3 ─O─CH 3 CH 3 ─CH 2 ─O─CH 3 CH 3 ─O─CH 3 CH 3 ─CH 2 ─O─CH 3 dimethyl ether ethyl methyl ether dimethyl ether ethyl methyl ether

27 Boiling Points of Ethers Ethers are only modestly polar.are only modestly polar. have an O atom, but there is no H attached.have an O atom, but there is no H attached. cannot form hydrogen bonds between ether molecules.cannot form hydrogen bonds between ether molecules.

28 Solubility of Alcohols & Ethers in Water Alcohols and ethers are more soluble in water than alkanes because the oxygen atom can hydrogen bond with water.are more soluble in water than alkanes because the oxygen atom can hydrogen bond with water. with 1-4 C atoms are soluble, but not with 5 or more C atoms.with 1-4 C atoms are soluble, but not with 5 or more C atoms.

29 Comparing Solubility & Boiling Points Molar Boiling Soluble Molar Boiling Soluble Compound Mass Point (°C) in Water? Compound Mass Point (°C) in Water? Alkane CH 3 ─CH 2 ─CH No Ether CH 3 ─O─CH Yes Alcohol CH 3 ─CH 2 ─OH 4678 Yes

30 Ethers as Anesthetics Anesthetics inhibit pain signals to the brain.inhibit pain signals to the brain. like diethyl ether CH 3 ─CH 2 ─O─CH 2 ─CH 3 were used for over a century, but caused nausea and were flammable.like diethyl ether CH 3 ─CH 2 ─O─CH 2 ─CH 3 were used for over a century, but caused nausea and were flammable. developed by the 1960’s were nonflammable.developed by the 1960’s were nonflammable. Cl F F Cl F H Cl F F Cl F H │ │ │ │ │ │ │ │ │ │ │ │ H─C─C─O─C─HH─C─C─O─C─H H─C─C─O─C─HH─C─C─O─C─H │ │ │ │ │ │ │ │ │ │ │ │ F F F H F H F F F H F H Ethane(enflurane) Penthrane Ethane(enflurane) Penthrane

31 MTBE Methyl tert-butyl ether CH 3 CH 3 │ CH 3 ─O─C─CH 3 │ CH 3 CH 3 is second in production of organic chemicals.is second in production of organic chemicals. is an additive used to improve gasoline performance.is an additive used to improve gasoline performance. use is questioned since the discovery that MTBE has contaminated water supplies.use is questioned since the discovery that MTBE has contaminated water supplies.

32 Thiols are carbon compounds that contain a –SH group.are carbon compounds that contain a –SH group. are named in the IUPAC system by adding thiol to the alkane name of the longest carbon chain.are named in the IUPAC system by adding thiol to the alkane name of the longest carbon chain. the -SH group may also be called a “mercapto” groupthe -SH group may also be called a “mercapto” group

33 Thiols Thiols often have strong odors.often have strong odors. are used to detect gas leaks.are used to detect gas leaks. are found in onions, oysters, and garlic.are found in onions, oysters, and garlic.

34 Oxidation of Thiols When thiols undergo oxidation, an H atom is lost from each of two –SH groups.an H atom is lost from each of two –SH groups. the product is a disulfide.the product is a disulfide. [O] [O] CH 3 ─SH + HS─CH 3 CH 3 ─S─S─CH 3 + H 2 O

35 Aldehydes and Ketones An aldehyde contains a carbonyl group (C=O), which is a carbon atom with a double bond to an oxygen atom. In a ketone, the carbon of the carbonyl group is attached to two other carbon atoms.

36 Naming Aldehydes

37 Aldehydes in Flavorings Several naturally occurring aldehydes are used as flavorings for foods and fragrances. Benzaldehyde (almonds) Cinnamaldehyde (cinnamon)

38 Naming Ketones as IUPAC, the -e in the alkane name is replaced with –one.as IUPAC, the -e in the alkane name is replaced with –one. With a common name, the alkyl groups attached to the carbonyl group are named alphabetically followedWith a common name, the alkyl groups attached to the carbonyl group are named alphabetically followed by ketone. by ketone. O O O O ║ ║ ║ ║ CH 3 ─C─CH 3 CH 3 ─C─CH 2 ─CH 3 propanone 2-butanone (dimethyl ketone) (ethyl methyl ketone) (dimethyl ketone) (ethyl methyl ketone)

39 Ketones in Common Use Nail polish remover, solvent Propanone, Dimethylketone, Acetone Butter flavoring

40 Classify each as 1) aldehyde or 2) ketone. O O || || || || A. CH 3 —CH 2 —C—CH 3 B. CH 3 —C—H CH 3 O CH 3 O | || | || C. CH 3 —C—CH 2 —C—HD. | CH 3 CH 3 Learning Check

41 Properties of Aldehydes & Ketones The polar carbonyl group provides dipole-dipole interactions.The polar carbonyl group provides dipole-dipole interactions.  +  -  +  -  +  -  +  - C=O C=O Without an H on the oxygen, aldehydes and ketones cannot form hydrogen bonds to each other.Without an H on the oxygen, aldehydes and ketones cannot form hydrogen bonds to each other.

42 Boiling Points Aldehydes and ketones have polar carbonyl groups (C=O).polar carbonyl groups (C=O).  +  -  +  -C=O attractions between polar groups.attractions between polar groups.  +  -  +  -  +  -  +  - C=O C=O higher bp’s than alkanes and ethers of similar mass.higher bp’s than alkanes and ethers of similar mass. lower bp’s than alcohols of similar mass.lower bp’s than alcohols of similar mass.

43 Comparison of Boiling Points

44 Solubility in Water The electronegative O atom of the carbonyl group of aldehydes and ketones forms hydrogen bonds with water.

45 Tollens’ Test Tollens’ reagent,Tollens’ reagent, which contains Ag +, oxidizes aldehydes, but not ketones. Ag + is reduced to metallic Ag, which appears as a “mirror” in the test tube.Ag + is reduced to metallic Ag, which appears as a “mirror” in the test tube.

46 Benedict’s Test Benedict’s reagent, which contains Cu 2+, reacts with aldehydes that have an adjacent OH group.Benedict’s reagent, which contains Cu 2+, reacts with aldehydes that have an adjacent OH group. An aldehyde is oxidized to a carboxylic acid, while Cu 2+ is reduced to give red Cu 2 O(s).An aldehyde is oxidized to a carboxylic acid, while Cu 2+ is reduced to give red Cu 2 O(s).